Rutland Water Nature Reserve is known mainly for its significant wintering populations of wildfowl, and the increasing population of ospreys that breed here in the summer. It is easy to forget or take for granted the other wildlife that occurs on the nature reserve. It is not just ospreys that are endangered and were re-introduced to this area…

Water voles are members of the rodent family, and are often confused with rats. However, they differ from rats in many ways, not least in that they are under threat, and rats are not. Water voles, as the name suggests, like to live near water. They occur at the fringes of ponds, lakes and other bodies of still water such as canals, but are just as at home on the banks of rivers and streams. They live and breed in burrows that they dig into the soft mud of the banks, and feed mainly on vegetation such as reeds.

Historically, water voles were widespread throughout Britain, but their population suffered a dramatic decline during the 20th century – one of the most serious declines of all British mammals. This population decline was due mainly to the presence of mink, but also habitat fragmentation and water pollution. Mink are a non-native species that were brought to the UK in the 1920s for use in fur farms, and either escaped or were released, and had begun breeding in the wild by the 1950s. Unfortunately, mink are very efficient at predating water voles, and are their main threat.

It was soon realised that something needed to be done to replenish the population of water voles at Rutland Water. Consequently, a license was granted and a re-introduction programme for water voles took place in 2011, in conjunction with a programme of mink control. Click here for more information. It worked incredibly well, and there is now a thriving population of water voles on the nature reserve and in the surrounding area.

The population of water voles on the reserve has been monitored closely ever since the re-introduction, by volunteers Linda and Anthony Biddle. These surveys are carried out by the simple but effective method of counting the number of droppings on specially made “rafts”. Water voles like to keep their burrows clean by using flat areas of mud or grass as latrines. They will also often use areas such as this as feeding stations. With this in mind, several small rafts were made and installed in all locations likely to contain water voles. The voles then use these rafts as latrines, and surveyors visit the locations of these rafts and count the number of water vole droppings that appear on them.

Last week was my first water vole droppings count, and I really enjoyed it! It was a beautiful autumn day, and I was content to be wandering slowly up and down channels and water courses in the peace and quiet, locating the rafts, counting the droppings and noting the number on a recording form. It was amazing just how many droppings there were in some places! Water voles have definitely become well established on the nature reserve following the re-introduction – another success story!

The population will continue to be monitored over the coming years, and the data from previous surveys has been collated, reviewed and written up in the form of reports. The surveys are carried out every quarter, and a report is made of each survey, then at the end of the year an annual report will be created. The other ongoing task is to monitor the population of mink, which is done in a similar fashion but using special mink rafts, which contain a platform of clay in the centre to retain the footprints of any animal that passes over it, alerting us to the presence of mink in that area, should there be any.

Water voles are not a species that can be spotted easily, as they are rather elusive and live mainly under the protective cover of tall waterside vegetation. If you are lucky you may see one swimming away from you, but more likely you will just hear the “plop” of them entering the water when they hear you coming. Water voles have often been spotted in the channels in front of Waderscrape hide on the Lyndon reserve, and here you stand more of a chance of seeing them sitting on the banks, as there is the advantage of being able to sit in the hide and make no noise, making it more likely they will show themselves.

Look out for more updates on water voles and surveys in the near future!